Foreign Minister Sergey Lavrov said Kim's response had been "positive, as a first signal," a statement that echoed earlier comments by Russian President Vladimir Putin's foreign affairs adviser. Lavrov didn't elaborate.

North Korea has not officially commented on the invitation and still has time to decline it.

Moscow has invited many global leaders — including Kim and the presidents of China and South Korea — to May celebrations marking the 70th anniversary of the Soviet Union's victory over Nazi Germany, which will feature a Red Square parade.

If Kim accepts, the trip to Moscow could be his first trip abroad since taking power three years ago.